Direct Attack without Entry. Open the door slightly and direct a solid stream of water at the seat of the class A fire. Keep in mind that a solid stream of water can be projected approximately 75 feet when 100 psi is available at the fire main. This method of extinguishment may be desirable when the compartment has become superheated and entry by the fire fighters would result in too much body punishment to the fire fighters.
Indirect Attack (for Smaller Compartments). Fire extinguishment can be effected by briefly opening the door to the compartment that is on fire and then directing high-velocity fog into the overhead of the compartment. The superheated gases in the overhead will flash this water to steam and the steam will begin to fill the compartment. When sufficient steam has been generated in the compartment, close the door tightly and allow the steam to smother the fire. This method is useful for small compartments where the fire has progressed to the second or the third stage and the gases in the overhead have become superheated.
Direct Attack Using Proper Technique. Fire fighters enter the compartment and stay low to the deck. The 4-foot applicator is used for heat shielding and personnel cooling. As little water as possible is used from the attack nozzle so as not to stir up the thermal boundary in the overhead. The source of the fire is approached as closely as possible without using water. Solid stream is used directly on the seat of the class A fire.
Direct Attack Using Improper Technique. The result of this is that the water reaching the superheated gases in the overhead flashes to steam. The turbulence of the high velocity fog causes the thermal boundary to become disturbed. The superheated gases and steam are forced down to the deck from the overhead with the result that the fire fighter will be forced out of the compartment by overheating.
